I've been tasked with finding a public address system for an event in July. It will be held in one corner -- about 150-feet by 200-feet -- of a much larger (~180,000 sq. ft.) airplane hangar. The ceiling is more than 50 feet high.

The event will have about 100 people and the system will be just for announcements as well as a door-prize giveaway. No music.

What size of a system will I need? Can someone recommend the size/number of speakers? Total wattage?

A secondary question: I Googled through some AV rental agency web sites and it looks like a fairly small system -- 1000 watts, two 15-inch speakers on stands, a wireless mic -- is going to cost $500 to rent for the five-day event. It looks like a system of about that size could be purchased for the same amount. Is that correct? If the non-profit group is going to have to cough up $500, shouldn't we just buy rather than rent?

2 x JBL EON210P + speaker stands JBL-SS2-BK + Shure SM58 microphones, cables and stands. All top line package cost for four mics and all $1,750 and you can sell it in 5 minutes after you are done with it for almost that. (Check eBay & Craig's list.)

You can buy cheaper, but for a real 5 day event I would not. Of course if it is a charity ask the AV dept. at a local college for a system. If it is summer, they should still charge you, but around $100.

You surely do not need 1000 watts and 15" speaker cabs to do voice announcements. And you are not planning to fill the hangar with sound, and there will not be a packed house of bodies to absorb sound.

SOmething basic and portable like a Fender Passport system would do. There is no stereo to worry with, no audio imaging or other hi falutin concern. Other companies make portable PA systems for the basics, Peavey Messenger for example.

You should be able to find a rental place that can handle the basics. Do yourself a favor and CALL them and ask after your needs. DOn;t rely on just what you see on theiur web sites. ANd in addition to AV rental places, contact local music stores. Many of them do rentals.

This is exactly the sort of sound system they would use in for example, sales meetings or training sessions at the local hotel facility. Auctioneers use basic portable systems.

ANd what simon said, I think even just ONE JBL Eon with a microphone plugged into it would probably be enough. Many JBL Eon models include a very basic preamp that will take a microphone.

ANd have you checked at the hangar? Is there an existing paging system? Is it the sort of place with a front office and speakers out in the hangar proper to call mechanics up front? Tapping into that ought to be free.

If you need wider coverage and use two speakers think about putting them next to each other splayed apart. Putting them next to each other in what most likely is a big reverb chamber will help some on the intelligibility of the system. If possible put them front and center of the area to be covered.

Wow , first you've got to many issues with that building to name.
180,000 sq ft would be the first.
Next is whoever wants to charge you $500 for a couple of 15's with power for a week is out of thier minds. FInd a guy who understands the issues of room with a decent PA and hire him.
How many people , if its a nice day tell them to open bothe ends of the hangar , it might help !
Next if these people are rich , Im thinking they probably are if thier holding a little gig in a hangar that big, then charge them serious money to get a serious system.
Ask them realistically what they expect for sound ? , then explain in detail the issues associated with a "Cavern" that big.
If the place was going to be full of people that would change the whole perspective. But a hundred people , really .
The idea of using a single point source actually is a good idea.
It helps eliminate phase issues associated with multiple echo return paths.
Hope this helps , but I feel for YA.
Cheers...FFT dude